Identification of the leptin mutation in the ENU-induced obese mice.

<p>(<b>A</b>) Mating and screening strategy for isolation and maintenance of the ENU-induced obese mice. The detail of breeding strategy is summarized in the <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0015333#s4" target="_blank">Materials and Methods</a>. (<b>B</b>) Mapping and haplotype analysis for the mutation in the ENU-induced obese mice. Black boxes represent homozygotes for C57BL/6J/C57BL/6J and white boxes represent either C57BL/6J/BALB/c heterozygotes or BALB/c/BALB/c homozygotes. The number of progeny inheriting each haplotype is listed in the bottom. Haplotype analysis indicates that the mutation falls within a 2.6 Mb region (arrow) between rs33791073 and rs13478688 on chromosome 6. (<b>C</b>) Sequencing traces a T-to-A transversion (asterisk) in exon 3 of <i>Leptin</i> gene, causing a V145E substitution. (<b>D</b>) Val-145 and its nearby amino acids, located in the N-terminal of helix D (box) of leptin protein, are conserved throughout species.